| 0 ≤ i, j < i, ∀ j0, i, intfun, intfun0. i→n(j0) < i→n(j) → 0 ≤ i → Σ countFun(i, j0, intfun) = Σ countFun(i, j0, λ i0. intfun(i0) - intfun0(i0)) + Σ countFun(i, j0, intfun0) ⊦ 0 = Σ countFun(i, j, λ i0. intfun(i0) - intfun0(i0)) |
⊦ j < i → countFun(i, j, intfun) = []
Used simplifier rules: sum-empty: ⊦ Σ [] = 0; Used terms: λ i0. intfun(i0) - intfun0(i0), j, i